Mishkin, Frederic
What do we mean by price stability? A widely cited definition is that the inflation rate is sufficiently low so that households and businesses do not need to take inflation into account in making everyday decisions.3 Broadly speaking, I believe this definition of price stability is a reasonable one, and in practice, central banks around the world have chosen average levels of inflation between 0 and 3 percent as consistent with this criterion. However, this range can be narrowed a bit further by considering the implications of economic theory and empirical evidence about the average inflation rate that produces the best economic outcomes...
In contrast, given shocks like those seen over the past several decades, an average inflation rate higher than about 1 percent substantially reduces the frequency with which the economy hits the zero lower bound. An inflation objective of about 2 percent implies that monetary policy is rarely constrained by the zero lower bound and thereby minimizes the adverse consequences for macroeconomic stability.